[EN]Some were kinetically studied alkylation reactions with DNA model molecules . By its reactivity with nucleophilic centers present in biological media , we investigated the capability of the following alkylating aliphatic and aromatic epoxides : propylene and butylene oxides , cis - and trans -2 ,3- epoxybutanes , styrene oxide and oxides of p - chlorostyrene , p - bromostyrene and p - nitrostyrene .Has been used as model molecule 4 - (p - nitrobenzyl) pyridine , similarly to the N7 position of guanosine nucleophilicity . Along with the study of the mechanisms of the reactions studied and the influence of these substituents on the oxirane ring have been investigated kinetically competing reactions that characterize these mechanisms and have tried to correlate chemical reactivity , biological activity .It has come to the following conclusions :i ) All epoxides studied show on NBP alkylating activity .ii ) To understand the ability of alkylating epoxides is necessary to consider the possible competing reactions : a) said alkylation of NBP itself . With aliphatic epoxides occurs in the least substituted carbon of the oxirane ring through a SN2 mechanism forming a stable adduct , which is hydrolyzed . Aromatic epoxides with further proceeds in the carbon substituted by a SN2 mechanism ' by forming a stable adduct , b) hydrolysis of the unstable epoxide adducts NBP c) hydrolysis of epoxides . Forgetting some of these reactions has caused frequent erroneous conclusions identified in the literature.iii ) The study of the reactivity of epoxides as alkylating agents requires evaluating the molar ratio of each of the adducts formed absorption . The assumption of some approaches that bypass these measures found in the literature can be misleading .iv ) The sequence of reactivity for alkylation of NBP by epoxies is the same as the hydrolysis thereof, and adducts formed from the unstable oxides of styrene > linear epoxides monosubstituted > disubstituted epoxides linear .v ) There is a correlation between in vitro mutagenesis and chemical reactivity of the oxirane of the same type .Alkylation of the N7 position of guanosine DNA facilitates adoption of the Z conformation may lead to mutagenesis and carcinogenesis.We have taken the first steps in the study of BZ DNA conformational change mediated by different promoters : two divalent metal cations , Ni ( II ) and Zn ( II ) and ethanol, dehydrating solvent DNA . As repetitive sequences facilitate bp DNA conformational change has been used as a model polynucleotide, poly ( dGdC ) poly ( dGdC ) . The kinetic study of the conformational change has led to the following conclusions:i) The trend found for the efficient induction of conformational change promoting agents BZ for singly , Zn ( II ) > EtOH > Ni ( II ) , suggesting that the process of transfer of the cation from the water to the hydrophobic surface of DNA is involved a drying process .ii) ethanol / metal ion mixture BZ transition induced more effectively than each promoter ( EtOH or metal ion ) separately . The synergistic effect is due to the fact that separate promoters induce the transition B Z ? Poly ( dGdC ) poly ( dGdC ) while mixing ( EtOH / metal ion ) produces an aggregated form of the families of the Z.iii) DNA conformational change promoted by Ni ( II ) and Zn ( II ) has shown that the transition of the poly ( dGdC ) of form B , clockwise , to Z, or levorotatory form aggregate depends Z * the temperature acts as a selective factor .iv ) The values ​​of the constants observed for the conformational change ZB , greater than those associated with the change BZ , reveal that the reverse conformational change , ZB , is more facilitated than direct , BZ .CONTENTS:1. Introduction .Two . Kinetic study of alkylation of DNA molecules by epoxides model . 2.1. Bibliographic report. 2.2 . Kinetic study of the alkylation of DNA molecules by linear model epoxides . 2.3 . Kinetic study of the alkylation of DNA molecules by model styrene oxides . 2.4 . Comparative study of linear and aromatic epoxides.Three . Other kinetic studies using model molecules : Kinetic study of DNA conformational change.